1. Field of the Invention
This invention relates to a pharmaceutical, particularly a triazole derivative useful as an antifungal agent.
2. Description of the Related Art
Based on the infected regions, mycosis is roughly divided into superficial mycosis such as marginated eczema, psoriasis, various types of trichophytosis, skin Candida infection and the like and deep mycosis such as fungal meningitis, fungal respiratory organ infection, fungemia, mycosis of urinary tract and the like. The later cases among them are infections in which the whole body organs and tissues are affected by fungi, and many of them have a particularly increasing tendency in recent years due to the use of chemotherapeutic agents, frequent use of immunosuppressants by organ transplantation, lowering of immunity in the living body by AIDS infection and the like. As the deep mycosis, aspergillosis, Cryptococcosis, candidiasis, zygomycosis and the like can be exemplified, but drugs effective for these are rare. As the therapeutic drugs to be used, a polyene macrolide antibiotic substance Amphotericin B (U.S. Pat. No. 2,908,611) and a fluoropyrimidine compound Flucytosine (U.S. Pat. No. 2,802,005) are typical. However, these drugs have problems in that side effects are strong, resistant strains are apt to appear, and the like.
On the other hand, a great number of azole system compounds having antifungal actions have been developed and put on the market in recent years. These compounds have actions to inhibit metabolic enzymes useful in biosynthesizing ergosterol which is necessary for keeping cell membrane functions, and for example, Fluconazole (JP-A-58-32868), Ketoconazole (JP-A-53-95973), Voriconazol (European Patent Application No. 440372) and the like are known. However, it is hard to say that these are sufficient from the viewpoint of antifungal spectrum, pharmacokinetics, side effects and the like. In order to solve these problems, concern has been directed toward the development of a compound which is excellent in safety and also has further strong antifungal activity.